Seed balls with bauxite mining technosol: an alternative forest restoration technique in the Brazilian Atlantic Forest

This study aims to evaluate the effectiveness of technosol, composed of clay cake and organic compost, as a substrate for seed balls using native species from the Atlantic Forest. We investigated how different substrate compositions and the addition of NPK fertilizer influence the emergence, survival, and growth of four native tree species: Senna macranthera , Enterolobium contortisiliquum , Pterogyne nitens , and Anadenanthera peregrina . Seedling emergence and survival were monitored continuously over 190 days, and growth performance was evaluated using logistic growth models. The results showed that, in terms of emergence and survival, treatments without NPK addition yielded the best outcomes, regardless of the proportion of clay cake and organic compost. Growth models revealed that non-pioneer species ( P. nitens and A. peregrina ) performed better under treatments without NPK, while pioneer species ( S. macranthera and E. contortisiliquum ) exhibited higher growth rates in treatments with NPK. These findings emphasize the importance of aligning substrate composition and fertilization with the ecological strategies of different species to optimize restoration outcomes. The use of technosol-based seed balls derived from bauxite mining represents a viable alternative for forest restoration, promoting biodiversity recovery, reducing waste disposal in tailings dams, and contributing to circular economy principles in the mining sector.